Disinfectants are nonspecific with respect to both mechanism of action and spectrum of activity. They are also not tolerated by the host

What is the basis of selective toxicity

Absence of the target from the host; permeability differences; structural differences in the target. Also, antimicrobial agents must be effective against bacteria at concentrations that are not deleterious to the host

What considerations must antibiotic therapy include

Effect of the drug on the microbe; effect of the microbe on the drug; effect of the microbe on the host; drug-host interactions